Semiconductor etching apparatus and method of etching semiconductor devices using same

Abstract

A semiconductor etching apparatus and a method for etching semiconductor devices using the apparatus. The semiconductor etching apparatus includes a chamber for accommodating a wafer, a radical source for supplying a radical into the chamber, a beam source for supplying ion beams or plasma into the chamber, a wafer stage for supporting and holding the wafer accommodated by the chamber, and a neutralizer for neutralizing charge within the chamber ionized by the ion beams, plasma or the radical. The method of etching semiconductor devices includes the steps of forming a reaction layer on the surface of a semiconductor wafer through radical absorption, and etching the surface of the semiconductor wafer by desorbing the reaction layer formed on the surface of the semiconductor wafer.

What is claimed is:  
     
         1 . A semiconductor etching apparatus comprising: 
 a chamber for accommodating a wafer;    a radical source for supplying a radical into the chamber;    a beam source for supplying one of ion beams and plasma into the chamber;    a wafer stage for supporting and holding the wafer accommodated by the chamber; and    a neutralizer for neutralizing charge within the chamber ionized by the ion beams, plasma or the radical.    
     
     
         2 . The semiconductor etching apparatus of  claim 1 , wherein the beam source is an inductive coupled plasma apparatus and wherein a beam energy of the beam source is adjustable.  
     
     
         3 . The semiconductor etching apparatus of  claim 1 , wherein the beam source can accelerate the generated plasma or ion beams using three grids comprising a beam grid, an accelerating grid and a ground grid.  
     
     
         4 . The semiconductor etching apparatus of  claim 2 , wherein the beam source can accelerate the generated plasma or ion beams using three grids comprising a beam grid, an accelerating grid and a ground grid.  
     
     
         5 . The semiconductor etching apparatus of  claim 1 , wherein the radical source can form the plasma and eject the radical into the chamber.  
     
     
         6 . The semiconductor etching apparatus of  claim 5 , wherein the plasma is formed by an inductive coupled plasma method.  
     
     
         7 . The semiconductor etching apparatus of  claim 1 , wherein the neutralizer supplies electrons into the chamber cationized by the ion beams, plasma or the radical, thereby neutralizing the atmosphere of the chamber.  
     
     
         8 . The semiconductor etching apparatus of  claim 7 , wherein the neutralizer is a hollow cathode emitter.  
     
     
         9 . The semiconductor etching apparatus of  claim 1 , wherein the wafer stage comprises a cooling apparatus for cooling the accommodated wafer.  
     
     
         10 . A method of etching semiconductor devices, comprising the steps of: 
 forming a reaction layer on the surface of a semiconductor wafer through radical absorption; and    etching the surface of the semiconductor wafer by desorbing the reaction layer formed on the surface of the semiconductor wafer.    
     
     
         11 . The method of  claim 10 , wherein the surface of the semiconductor wafer is composed of two different layers, an etching object layer and an other layer, the reaction layer is formed on the etching object layer and the other layer, and the surface of the semiconductor wafer is etched by desorbing the reaction layer formed thereon such that the etching selectivity of the etching object layer to the other layer is high.  
     
     
         12 . The method of  claim 10 , wherein the etching object layer on the surface of the semiconductor wafer is etched by repeatedly performing the step of forming the reaction layer through radical absorption and the etching step through radical desorption two or more times.  
     
     
         13 . The method of  claim 11 , wherein the etching object layer on the surface of the semiconductor wafer is etched by repeatedly performing the step of forming the reaction layer through radical absorption and the etching step through radical desorption two or more times.  
     
     
         14 . The method of  claim 12 , wherein the beam energy of ion beams or plasma is set such that the other layer except the etching object layer is rarely etched to thereby increase the etching selectivity when the etching object layer on the surface of the semiconductor wafer is etched, by repeatedly performing the reaction layer forming step through radical absorption and the etching step through radical desorption.  
     
     
         15 . The method of  claim 14 , wherein the etching object layer is a SiO 2  layer, and the other layer is Si 3 N 4  layer.  
     
     
         16 . The method of  claim 15 , wherein the beam energy of the ion beams or plasma necessary for increasing the etching selectivity of the SiO 2  layer to the Si 3 N 4  layer is 90-110 eV.  
     
     
         17 . The method of  claim 10 , wherein the radical absorption is accomplished using a radical source for supplying a radical into a chamber accommodating a wafer.  
     
     
         18 . The method of  claim 17 , wherein a mixed gas of a gas containing H and N and a gas containing F is used as the radical source gas.  
     
     
         19 . The method of  claim 18 , wherein the mixed gas of a gas containing H and N and a gas containing F has a H/F ratio of 1.0 or higher.  
     
     
         20 . The method of  claim 10 , wherein the etching through the desorption of the reaction layer formed on the semiconductor wafer is accomplished using ion beams or plasma, and wherein the source of the ion beams or plasma is an inert material.